The present invention relates generally to chair control mechanisms, and more particularly to a tilt control apparatus employing a torsion bar adapted to bias a backrest of the chair toward an upright position.
It is conventional to provide a chair having a backrest that is supported on a base for pivotal movement about a horizontal axis between upright and reclined positions such that a person can recline to a limited ex-tent while seated in the chair. It is further conventional to employ a tilt control apparatus in the chair, wherein the tilt control apparatus is connected between the base and the backrest of the chair, and includes a spring that biases the backrest toward the upright position relative to the base.
More recently, such tilt control apparatuses have be designed for use on relatively inexpensive, lightweight stacking chairs of the type commonly used by convention hall owners and others for large gatherings or services. This type of chair must be stacking to facilitate storage of large numbers of chairs, while being easy to unstack and position for use.